Snow came too late to prevent septic system freeze ups

Another cold, dry winter has flooded local plumbing contractors with repair calls for frozen septic systems. Warm weather and a fresh blanket of snow haven't reduced problems to a trickle, but at least they're keeping up, Bemidji plumbing, heatin...

Another cold, dry winter has flooded local plumbing contractors with repair calls for frozen septic systems.

Warm weather and a fresh blanket of snow haven't reduced problems to a trickle, but at least they're keeping up, Bemidji plumbing, heating and septic system contractor Tom Wagner said.

Wagner said his office handled literally hundreds of calls and were backlogged at times up to a week during the extended cold snap that spanned much of January and February.

"The snow will help," Wagner said, "but a lot of it is too late; the frost is already in the ground."

During an average winter where a foot or more of snow is on the ground in November, Wagner said frost might only penetrate 6 inches. This winter he said frost is reaching depths of up to 4 feet.


"In systems that are 3 feet deep or less, the tanks are freezing up," Wagner said.

In some cases, Wagner said problems have been averted by installing a septic system heater, which costs around $40.

He has also been recommending to those who live alone or are conscientious about conserving water to not skimp when it comes to using hot water if there are concerns about the septic system freezing.

Though the University of Minnesota Water Resources Center typically encourages water conservation, when it comes to septic systems that could potentially freeze, advice from the Extension's on-site sewage treatment program is the same.

Use water -- the warmer the better if you feel the system is starting to freeze -- this includes spreading out your laundry schedule, doing one hot load a day, using a dishwasher or taking a hot bath.

However, the Water Resources Center warns not to leave water running all the time, as this will hydraulically overload the system.

Other causes

While cold temperatures coupled with a lack of snow are the largest causes of frozen septic systems, the Water Resources Center has compiled a list of other potential contributors.


Compacted snow will not insulate as well as un-compacted snow. Driving any type of equipment over the system can send frost down deeper. Automobiles, snowmobiles, ATVs, people and livestock should stay off the system all year long, but especially in the winter.

Any time traffic over a sewer pipe, septic tank or soil treatment is expected, insulated pipe should be used.

Compacted soil also tends to freeze deeper, which can affect septic system components in the area.

When a fixture such as a toilet or showerhead leaks, it can send a small trickle of water into the system. The slow moving thin film of water can freeze within the pipe and eventually cause the pipe to freeze solid.

Another common cause of freeze ups, according to the Water Resources Center is improperly draining pipes. Any time a dip or low spot occurs in a pipe, sewage can collect and freeze.

Check for open, broken and uncapped risers or inspection pipes, which could allow cold air to enter the system.

If water is coming to the surface or seeping from a mound, repairs need to be made. Systems that are hydraulically failing are prime candidates for freezing, according to the Water Resources Center.

Prevent problems


A few recommendations from the Water Resources Center to prevent headaches next season include placing an extra layer of mulch 8-12-inches deep over the pipes, tank and soil treatment system to provide extra insulation. Mulch can be straw, leaves, hay or any other loose material that will not compact and will stay in place.

Letting the grass in your lawn get a little longer in late summer over the tank and treatment area will provide extra insulation along with helping to hold snow.

If you know you are going to be gone for an extended period of time, plan accordingly. This could include having someone use sufficient quantities of in the home or pumping out your septic tank before leaving.

What not to do

There are many misconceptions about dealing with a frozen system according to the Water Resources Center. Homeowners should never add antifreeze, salt or an additive into the system.

Never pump sewage onto the ground, start a fire over the system or run water continuously to try to unfreeze the system.

Calling a professional to steam jet the system, installing a tank heater or letting the system thaw naturally are the only ways to remedy a system that has frozen, according to the Water Resources Center.

Once a system has frozen, homeowners may need to use the septic tank as a holding tank until the system thaws naturally. Depending on a household's water use, hiring someone to regularly pump the tank until the system thaws naturally can be costly.

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